import numpy as np
arr1 = np.zeros(2)
print('一维数组arr1: \n',arr1)

arr2 = np.zeros((2,3))
print('一维数组arr2: \n',arr2)

arr3 = np.ones(3)
print('一维数组arr3: \n',arr3)

arr4 = np.ones((3,3))
print('一维数组arr4: \n',arr4)

arr5 = np.empty(4)
print('一维数组arr5: \n',arr5)

arr6 = np.empty((3,4),dtype='int')
print('二维整型数组arr6: \n',arr6)